Rosneft's Vice President Mikhail Stavsky is quitting and more resignations among management are to follow, Kommersant business daily said on Friday.
The firm's President, Sergei Bogdanchikov, was replaced about a month ago.
Kommersant quoted Vice President Mikhail Stavsky as saying that he was leaving the company, Russia's largest oil firm, from Monday to start a new job. He declined to say why he was quitting Rosneft, where he had worked for four years and was responsible for production activities.
Rosneft declined to comment.
Kommersant quoted a Rosneft source saying Stavsky had a serious conflict with new President Eduard Khudainatov, although another Rosneft source said that Stavsky had just decided not to prolong this contract.
The paper said Oil Production Department head Gani Gilayev would take over Stavsky's duties.
Kommersant also said that other top managers could quit Rosneft in the near future, including Vice President Peter O'Brien, who organized the company's initial public offering in 2006.